It is difficult to answer the question “How long do viral infections last?” since there are many different types of viruses that cause many different infections.
What Causes Viral Infections
Viral infections are caused by viruses. A virus is a minuscule capsule that contains the virus’s genetic material. This small entity has only one purpose and that is to replicate or to grow in number. It does this by inserting itself into an individual’s genetic material and free loading. That is, when the individual’s genetic material replicates so does the virus’s. Its insertion causes many problems. It may affect the original product of the gene: protein, enzyme or hormone. As it grows in numbers it may destroy the patient’s cells causing the host to become sick.
How long Viral Infections Last Depends on the Particular Virus
To answer the question as to how long viral infections last, one has to look at the different types of infections caused by viruses. Viral infections can be classified into three main groups:
Acute Infections: These are severe infections that often make the individual feel uncomfortable and ill. They last for about a week but may also linger for a month. These types of infections are usually fought successfully by the body’s immune system. An example of this type of viral infection is the common cold. In this case the virus is usually one of the many different rhinoviruses.
Chronic Infections: These types of viral infections can last as long as a lifetime or as short as a few days. Their symptoms are normally not acute and infected individuals may not be aware of the infection. This causes the virus to be spread from person to person undetected. An example of a chronic infection is hepatitis C. This virus infects the liver where it starts a silent assault on the liver which may not be detected for a couple of decades. The result can be serious liver damage leading to liver cirrhosis or even liver cancer.
Latent Infections: These types of viral infections lay dormant in the infected individual indefinitely and will exhibit symptoms suddenly as the viruses “wake up.” They may remain dormant for long periods of time, waking up periodically and returning back to their dormant phase. When they are active they are contagious and can be transmitted to others. Latent viruses include viruses such as the chicken pox causing virus and the herpes simplex viruses.
Treating Viral Infections
Treating viral infections can be a challenge. The viruses tend to hide inside the host’s cells making them hard to find and destroy by anti-viral medications. (Most medicines work in the blood stream.) Most antiviral drugs are therefore designed to stop the replication process by inactivating the viruses. The best treatment for viruses is prevention. Vaccines prepare the immune system by allowing the body time to create antibodies against viruses before they invade the body. Antibiotics cannot treat a viral infection
When diagnosed with a viral infection expect the infection to last 7 to 10 days unless the virus is specifically identified as one that can cause a longer infection period.
National Institute of Allergy and Infectious Diseases (NIAID): Microbes Can Cause Difference Kinds of Infections